盖梁节段拼装施工关键技术

Key Construction Technology of Coping Segmental Assembly

DASH高架桥盖梁采用工厂短线法节段预制,现场进行节段匹配法安装。针对盖梁节段拼装过程中线形控制以及精轧螺纹钢临时锚固和预应力钢束张拉顺序进行分析研究,通过施工过程中监控量测对盖梁成桥线形进行控制,并在下一个节段预制过程中主动干预调整下一节段线形从而达到对已架节段线形进行纠偏,同时在施工各阶段通过有限元分析读取各阶段胶接面应力变化情况,分析数据显示胶接面不管在临时锚固或者预应力钢束张拉过程中,各施工阶段均能满足胶接面最大拉应力≤0,从而达到盖梁线形满足设计要求,以及预应力钢束张拉过程中梁单元应力平衡,不会出现节段之间胶接面的起拱或下挠,满足盖梁节段拼装锚固体系的安全性、耐久性要求。

DASH viaduct coping is prefabricated by factory short-line method and installed by segment matching method on site.This paper analyzes and studies the alignment control during the assembling process of the coping segment and the sequence of the temporary anchorage and tension of the pre-stressed steel bundle of the finished rolling thread steel.Through the monitoring and measurement in the construction process,the bridge alignment of the coping is controlled.In the precasting process of the next segment,the active intervention is made to adjust the next segment alignment so as to rectify the alignment of the erected segment.Finite element analysis reads the stress variation of the bonded surface in every stage,and the analysis data shows that the bonded surface can satisfy the maximum tensile stress of the bonded surface<0 in every construction stage,no matter in the process of temporary anchorage or prestressing tendon tension,so as to achieve the linearity of the coping to meet the design requirements,as well as the stress balance of the beam unit in the process of prestressing tendon tension,so that the bonded surface between segments will not appear.The arch or downward deflection meets the safety and durability requirements of the anchorage system of the coping segmental assembly.